Examination technique

1-Use of surface coil for one knee as seen below.

2-Each part of the body has its own coil which is proportionally with the shape of this part.

3-Field of view(FOV)=16 cm.
 When you increases the field of view, the organ of interest is decreased in size, while if you decreases the FOV, the organ of interest is increased in size(inverted relationship).

4-Protocol of examination:

-Sagital T1,T2, and proton density(most important image taken in knee).

-Coronal T2(ordinary T2, gradient or STIR).

-Axial T2.

-STIR means Short T1 Inversion Recovery.

-Proton density makes water intermediate between T1&T2(High TR and low TE).

If the water is black in T1, and white in T2, so it will be grey in proton density.

Proton density image is the most useful image used in the knee examination.

Look at the articular cartilage which is composed of water, if it is grey, so you are dealing

with proton density image or look to TR on the film well be high while TE is small.

T1

Gradient

STIR

T2